Progressive ovarian carcinoma induces synthesis of type I and type III procollagens in the tumor tissue and peritoneal cavity.

Increased serum concentrations of aminoterminal propeptide of type III procollagen occur in advanced ovarian cancer. To study their origin, we compared the expressions of type I and type III procollagens in ovarian tumor tissue and the peritoneal cavity with immunoassays for the propeptide domains of these procollagens. Samples of tumor cyst fluid, peritoneal ascitic fluid, tumor vein blood, and peripheral blood were obtained at operation from 50 women with malignant ovarian neoplasms and 61 women with benign neoplasms. The ascitic fluid concentrations of both type I and type III procollagen antigens were significantly higher in the malignant tumors than in the benign ones, but this difference was evident only for type I procollagen in the tumor cysts. The aminoterminal propeptide of type III procollagen concentration in the peripheral blood was higher in the patients with malignant tumors, whereas the concentrations were similar in the tumor veins. The enhanced type I procollagen synthesis in the malignant tumors did not affect the corresponding antigen in the blood. The findings suggest that progressive ovarian carcinoma invariably induces a fibroproliferative response, characterized by active expression of type I and type III procollagens. The increased circulating aminoterminal propeptide of type III procollagen is derived from the peritoneal cavity rather than from the tumor tissue via the ovarian vein.